Sonos causing high CPU usage after playback stopped (ref#HMNFG1) [Roon Investigating] (Tracking thread)

What’s happening?

· Other

Describe the issue

Roughly a year ago I installed Roon Rock on an Intel NUC7I7. It's been running reliably and silently up until I installed the latest update. Now when I get up in the morning the fan is running full blast and the NUC is fairly hot to the touch. Each time I find it in this state, I shut it down and restart it. It then runs just fine through the day. Cool and reliable as always. Then in the morning, the fan will be going full blast.

I'll try to attach the log files covering the time from the initial reboot yesterday through its current, fan full blast state.

The NUC is connected to the network via Ethernet. The music library is kept on a Synology NAS, also connected via Ethernet. Endpoints are primarily SONOS devices. The NUC runs headless in a well ventilated cabinet.

The fan was replaced on the NUC about a year ago when I first placed it into service as a Roon server. When the overheating began, I opened it up to check for dust accumulation and found it was just as clean as I left it when the fan was replaced.

Interestingly, it seems responsive even when in its overheated state.

Thank You

Describe your network setup

NUC connected via ethernet. Music Library on Synology NAS connected via ethernet. SONOS endpoint devises connected via a mix of Wifi, Sonosnet and Ethernet.

Here’s a screen shot showing current versions of the software,

Logs upon request.

Hi @Wayne_Foster,
Thanks for reaching out to us about this issue. We activated diagnostics on your Roon Server. In your logs we are seeing a lot of activity indicating a stuck buffer from your SONOS devices. Can you test whether disabling your SONOS zones relieves the problem.

I have seven SONOS devices. One has a sub paired and two are set up as stereo pairs. Any suggestion as to which device is having problems? If you see an IP address in the logs, I can track it down.

I don’t know what a stuck buffer is, but it strikes me that it would result in lost audio on the offending device. I haven’t seen that. The overheating I’ve seen apparently starts in the middle of the night and I notice the fan in the morning. Music is not playing during this time. Letting the NUC cook for a few hours (no music) doesn’t stop the fan. Only a reboot.

Since pretty much all my listening is conducted with SONOS devices, I will disable all of them this evening and see what happens. Note the overheating does not start EVERY night so it may be 48 hours or more before we can declare success. However, the last three mornings have been consistent with overheating.

Thanks

Noticed the NUC fan was spinning away at high speed and it was hot about an hour ago. Nothing playing. First time I have seen the overheating during the day. I promptly disabled all SONOS devices and waited. Waited about an hour. Fan was still spinning and it was still hot. Rebooted it and it cooled right down. I’ll watch it like a hawk for the rest of the day, but evidence is piling up that this is not a SONOS problem.

I had a similar issue: High CPU even when not playing.

I would be streaming to a Sonos 5 all day, and then it seemed that towards the end of the day my roon server would jump to 100% of 1-3 cores even though I had stopped playing. It would stay that way for hours until I rebooted it. Happened 3 days in a row. The log showed nothing really happening (a few [stats] entries). In addition, I saw no real network or disk activity. Oh, and the CPU was basically flatlined at 25 or 75%, depending on how many cores were in use.

i have the same issues. i also have sonos devices. but i limited to 1 room. i had no issues in the past year, no hardware changes. now the fan is spinning and the NUC gets really warm… even without any music playing. for now i found a solution by turning off the Turbo Mode in the BIOS and setting low power Mode aswell. now its nice and cold and quiet in the morning…

Another bit of info if it matters. I was using Sonos Streaming in “Other network devices”. I will now try the Air Play 2 version for my Sonos 5 in “Roon Tested”.

Related to that, my Sonos Amp (latest version) is being recognized as a WiiM Amp, which is odd. I also have a few Sonos Ones that are not recognized as Roon Tested as I expect from: Title of Page

Perhaps this is related to Sonos Streaming vs Air Play 2?

16 hours into the test and the NUC remains cool. ALL endpoints currently disabled including the many SONOS endpoints I had. Not sure what this proves. The next 24 hours should be interesting.

I’m seeking suggestions from Roon for what to test next. Hard to believe that simply having a SONOS endpoint connected would cause the NUC to overheat… but maybe. If so, what side of the ROON / SONOS line does the fault lie on?

As a software developer, my theory is that using Sonos Streaming requires transcode down to at least 24bit/48khz, and that process gets stuck in a loop somewhere. My reasoning is that I had the same issue with Sonos, and I had my Roon installed on a Linux NUC. This allowed me to see resource usage. I found the transcoding process would bounce one core up to 100% while playing, and it was very spiky. At some point after playback stopped, one core would peg to 100% and stay steady there — no more spikes, flatlined. There was little to no disk or network activity, and that tells me that a thread in RoonApplicance is stuck in a loop somewhere.

Hello All,

Thanks for the additional reports. We are discussing the Sonos aspect with the team and we were wondering if you could please confirm the below questions:

  1. If you have your Sonos zone enabled (and Roon Server is restarted after) but do not play to any zone, do you still notice the issue happen?
  2. Does the issue still happen if you have the Sonos zones enabled but play to a non-Sonos zone all day?

Thanks!

I have not seen the server get overloaded when I do not play using Sonos Streaming. I haven’t gone all day not playing music though.

Yesterday evening, I changed my audio devices to use the Roon Tested Sonos via AirPlay2. I’ve been using that all day, and so far there are no issues. Previous days, I was using Sonos Streaming from “Other network devices”.

One other note, I did change my server over to ROCK on a supported i3 NUC (same NUC as before). Unfortunately, that limits my ability to see CPU and memory usage.

My testing over the past 24 hours or so. Note that the overheating problem has been occurring since the recent upgrade. I’ve just been paying close attention to it for the past day or two… There is a bit more info here than previous posts.

  1. Roughly 7 SONOS devices connected via SonosNet. Noted overheating of the NUC sometime after a short listening session. Overheating started some time after pausing playback.
  2. Disabled all SONOS devices. Waited about an hour. NUC was still overheating so I rebooted it.
  3. Left it running after the reboot with NO SONOS devices connected. No issues after 24 hours.
  4. Enabled a Cambridge CNX player and started a playlist. Left it running about an hour. No issues.
  5. Paused playback and reenabled all SONOS devices. No playback. Waited an hour. No issues.
  6. Started a playlist on a single SONOS device. Actually a stereo pair of SONOS ones. Playback stalled about five cuts into the playlist. Roughly 20 minutes. No overheating. Restarted playback.
  7. Playback stalled again after about 5 minutes. No overheating. Restarted playback. This is getting old… Same play list as always. All cuts rip to FLAC from CD stored on a local NAS.
  8. NUC is now overheating. But it’s not constant. Fan will rev up, then settle down. No signs of this in prior cuts. Signal path screen shot below.
  9. I’m done with this. I’ll leave the server up so ROON can check analytics. Playback currently paused. I’ll use the SONOS controller for music this evening. Looking forward to a solution, not more testing.
    Screenshot 2024-12-06 at 4.24.32 PM
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I use an Arc and not seeing this problem at all but then I only have one Sonos zone in Roon and have two ikea speakers used as surrounds over Sonos net but don’t use them in Roon.

I’ve noticed the same with a non Rock deployment (Roon on Windows, Surface Laptop 4). I have 2 Sonos devices (and several non Sonos endpoints). Interesting your mentioning Sonos as I’ve had one Sonos endpoint playing in the evening on a sleep timer and the next morning the CPU on the core/server has Roon using at least 50% and the system fans are spinning while no endpoints have been playing for 6-8 hours. Reboot fixes it.

Dont know if its related, I have the server installed on mac, for a while now I have process RoonAppliance running and throttling the cpu even when its not playing or active. My laptop is constantly running with fans.

There looks to be a lot of evidence that “Sonos Streaming” leads to high CPU usage even after you stop playback. I know I can make it happen. Use Sonos Streaming for a while = high CPU and fans. Use AirPlay to the same Sonos, and all is fine.

There has been no information provided or mentioned regarding hardware diagnostics evaluations upon any NUC.

What about surrounding airflow to your NUC. Age, warranty, BIOS changes/upgrades of course a service call to a manufacturer at minimum is in order if you’re warranty allows.

Dust? Opening it up and cleaning if you’re not violating your warranty.

Booting up from Windows GO or other diagnostic tools and performing diagnostics

I think many of us are familiar with such an occurrence but nothing definitive spells out that it’s a SONOS or Roon issue it’s currently still under investigation.

Sometimes individual hardware failures coincide with updates given the scale of a large project

Seems like a big coincidence that playing for hours using AirPlay or Roon Ready works fine, but multiple people see issues only when using Sonos Streaming. Play to Sonos Streaming and the CPU pegs to at least 1 core per Sonos Stream for hours AFTER stopping playback. CPU never goes back down until a reboot. The RoonAppliance process goes to 100% and stays steady after you stop playback. In one case I streamed to 3 Sonos boxes, and the CPU for RoonAppliance went 300+% (I have a 4 core CPU).

I can say definitively that this is NOT a fan or BIOS problem. In this graph, 76.3% is 3 of 4 cores are pegged at 100%. That flatline never moved for 6+ hours AFTER I stopped playback. That explains why my fan was getting a workout. It was not dust (I know it’s clean – I checked). This only happens when I stream with Sonos Streaming. AirPlay works fine. Roon Ready works fine. Something about Sonos Streaming does not make RoonAppliance happy.

FYI, I was using Roon on an Ubuntu NUC. That’s what allowed me to see CPU utilization and what process was stuck in a loop. In an effort to solve this, I converted my NUC to ROCK (it is a supported NUC), but I still see the same issue. Only now, I have to listen for the fan because roon does not let you see system status with ROCK.

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I agree with your analysis Dave. You’re clearly on top of it and that’s certainly more supportive evidence.